1. Field of the Invention
This invention is directed to a method of manufacturing a sealed device having a Group III nitride compound semiconductor and connectable to an external source. More particularly, the invention is directed to a method of manufacturing a sealed flip-chip-type device and a sealed wire-bonding-type device not to be required separate sealing steps and to constitute a self-contained package which is electrically connectable to an external source.
2. Description of the Related Art
Flip-chip-type devices and wire-bonding-type devices containing Group III nitride compounds as semiconductors are known in the art. An example of such a flip-chip-type device is shown in FIG. 6A, in which the flip-chip-type device is designated by reference numeral 100.
Referring to FIG. 6A, a plurality of flip-chip-type device units 100 are integrated by a common Group III nitride compound semiconductor substrate 10 carrying a plurality of positive electrodes 11 and negative electrodes 12. As shown in FIG. 6A, during manufacturing the Group III nitride compound semiconductor substrate 10 is divided by an appropriate technique into a plurality of flip-chip-type devices 100, each of which comprises a segment of the Group III nitride compound semiconductor substrate 10, one of the positive electrodes 11, and one of the negative electrodes 12.
The flip-chip-type device 100 is then connected to an external member (or source) 6 and sealed by known techniques. Two examples of known techniques for making this connection are respectively shown in FIGS. 6B and 6C, in which the flip-chip-type device 100 is shown in an inverted position and connected to the external member 6.
According to first conventional technique depicted in FIG. 6B, the connection between the device 100 and the external member 6 is accomplished by forming bumps 1 on the external member (or frame) 6. One of the bumps 1 connects the positive electrode 11 to a first electrode of the external member 6, and the other of the bumps 1 connects the negative electrode 12 of the flip-chip-type device 100 to the second electrode of the external member 6. These bumps 1 comprise a gold ball or solder. After this connection is made, the flip-chip-type device 100 and a surface portion of the external member 6 are encased or sealed with a resin 3.
According to the second conventional technique depicted in FIG. 6C, first and second electrodes 21 and 22 of an internal member (or subframe) 20 patterned on the internal member 20 are connected respectively to the positive electrode 11 and the negative electrode 12 of the flip-chip-type device 100. Bumps 1 serve as electrical connection bridges for electrically connecting the first electrode 21 to the positive electrode 11 and the second electrode 22 to the negative electrode 12. Then, the internal frame 20 is attached to the external member (or frame) 6 via a conductive adhesive 4 and the electrode 21 is connected to a wire bonding 5. The device 100, the internal member 20, the conductive adhesive 4, the wire bonding 5, and a portion of the external member 6 are sealed together by the resin 3.
In each of the conventional techniques illustrated in FIGS. 6A and 6B, the resin 3, which is laminated after the flip-chip-type device 100 has been connected to the external member 6, leaves an empty gap 33 either between the device 100 and the external member 6 (in the first conventional technique of FIG. 6B) or between the device 100 and the internal frame 20 (in the second conventional technique of FIG. 6C). In order to prevent the gap 33 from forming, a specific resin, i.e., an underfill material, is used to fill the gap 33 area prior to sealing the entire surface of the device 100. The underfill material means that the resin has a low viscosity and a high fluidity.
The need to practice this additional filling step to prevent the formation of gaps 33 inherently obtained by these conventional techniques increases the costs of manufacture by increasing processing time. It would be a significant improvement in the art to provide a process in which the manufacturing efficiency is increased by avoiding the need for this filling step and avoiding the need for separate inspection checks to inspect, on an individual basis, the adequacy of the seal of each of the separate devices 100.
And with respect to the wire-bonding-type light-emitting device, sealing step by resin is carried out after separating the device into each chips.